Generally, an inverter type X-ray high voltage device for medical or industrial applications converts an AC voltage, which is supplied from a commercial power supply through an AC reactor, into a DC voltage using a converter circuit or a chopper circuit formed by a thyristor or a diode and inputs this DC voltage to an inverter circuit after smoothing the DC voltage with a capacitor. This inverter circuit controls the phase difference, the frequency, the pulse width, and the like of the inverter circuit using the resonance phenomenon of a resonance capacitor and the leakage inductance of a high voltage transformer. Then, a high voltage generator boosts the DC voltage to a high DC voltage, and this high DC voltage is applied to an X-ray tube which is a load.